1. Field of the Invention
The present invention relates to a storage control device, and to an error information management method for a storage control device.
2. Description of the Related Art
A storage control device provides to a host computer (hereinafter simply termed a host), a storage region based on, for example, a RAID (Redundant Array of Independent Disks), which is made by arranging storage devices such as, for example, hard disks in an array configuration. At least one or more logical volume is created on the physical storage region provided by this storage device group, and this logical volume is provided to the host. The host writes data into and reads out data from this logical volume by transmitting predetermined commands.
A plurality of storage devices may be connected in digi-chain mode by a circuit called a port bypass circuit. Or, alternatively, a technique is per se known of connecting a plurality of storage devices with crossbar switches (refer to Japanese Patent Laid-Open Publication 2003-303055).
If a plurality of storage devices present on the same path are connected together by the digi-chain method, when a fault occurs on any one from among these storage devices, it also becomes impossible to use all of the other normal storage devices which are on that path. This is because the path is interrupted. It would seem that, if a secondary path (a redundant path) were provided, it would be possible to access the normal storage devices by changing over from the primary path to the secondary path. However, time would be required to change over between the paths, so that the responsiveness of the storage control device would be deteriorated.
It should be understood that, by switchingly connecting the storage devices with the technique described in the above identified document, the throughput between the disk adapters and the storage devices is enhanced. However, in the technique of that document, no consideration is given to methods for detecting faults that occur on the storage devices, or to methods of recovering from such faults, so that room for improvement remains.